Cardiovascular Disease Flashcards
What is coronary heart disease?
Coronary heart disease (CHD) is a type of cardiovascular disease. It occurs when the coronary arteries have lots of atheroma in them, which restricts blood flow to the heart muscle
What can coronary heart disease lead to?
Myocardial infarction
How do atheromas form?
If the endothelium of the artery is damaged, white blood cells and lipids from the blood clump together under the endothelium to form fatty streaks. Over time, more white blood cells, lipids and connective tissue build up and harden to form a fibrous plaque called an atheroma
What do atheromas do?
Atheromas partially block the lumen of the artery and restrict blood flow, which causes blood pressure to increase
What are two types of disease that affect the artery?
- Aneurysm
2. Thrombosis
How do aneurysms form?
Atheroma plaques damage and weaken arteries. They also narrow arteries, increasing blood pressure. When blood travels through the weakened artery at high blood pressure, it may push the inner layers of the artery through the outer elastic layer to form a balloon like swelling - an aneurysm. The aneurysm may burst, causing a haemorrhage
Explain thrombosis
An atheroma plaque can rupture the endothelium of an artery. This damages the artery wall and leaves a rough surface. Platelets and fibrin accumulate at the site of damaged form a blood clot (a thrombus). The blood clot can cause a complete blockage of the artery, or it can become dislodged and block a blood vessel elsewhere in the body. Debris from the rupture can cause another blood clot further down the artery
What causes myocardial infarction?
The heart muscle is supplied with blood by the coronary arteries. This blood contains oxygen needed by the heart muscle to carry out respiration. If a coronary artery becomes completely blocked, an area of the heart muscle will be cut off from its blood supply, receiving no oxygen. This causes myocardial infarction which can cause damage or death of the heart muscle
What are common symptoms of a heart attack?
Pain in chest and upper body, shortness of breath and sweating
What happens is large parts of the heart are cut off from oxygen?
Complete heart failure can occur, which is often fatal
What are three very common risk factors for cardiovascular disease
- High blood cholesterol and poor diet
- Smoking
- High blood pressure
How does high blood cholesterol and poor diet increase the risk for CVD?
Cholesterol is one of the main constituents of the fatty deposits that form atheroma. Atheromas can lead to increased blood pressure and blood clots. This could block the flow of blood to the coronary arteries, which could cause myocardial infarction. A diet high in saturated fat is associated with high blood cholesterol levels. A diet high in salt increases the risk of CVD as it increases the risk of high blood pressure
How does smoking increase the risk for CVD?
Both nicotine and carbon monoxide, found in cigarette smoke, increase the risk of CVD. Nicotine increases the risk of high blood pressure. Carbon monoxide combines with Hb and reduces the amount of oxygen transported in the blood, and so reduces the amount of oxygen available to tissues. If the heart muscle doesn’t receive enough oxygen it can lead to a myocardial infarction. Smoking also decreases the amount of antioxidants in the blood - these are needed to protect cells from damage. Fewer antioxidants means cell damage in the coronary artery walls is more likely, and this can lead to atheroma formation
How does high blood pressure increase the risk for CVD?
High blood pressure increases the risk of damage to the artery walls. Damaged walls have an increased risk of atheroma formation, causing a further increase in blood pressure. Atheromas can also cause blood clots to form. A blood clot could block flow to the heart muscle, possible resulting in myocardial infarction. Anything that increases blood pressure increases the risk of CVD e.g. being overweight, not exercising and excessive alcohol consumption
